/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/NiagaraGraph.h
Gather all the change ids of external references for this specific graph traversal.
void GatherExternalDependencyData ( [ENiagaraScriptUsage](API\Plugins\Niagara\ENiagaraScriptUsage) InUsage, const [FGuid](API\Runtime\Core\Misc\FGuid) & InUsageId, [TArray](API\Runtime\Core\Containers\TArray)< [FNiagaraCompileHash](API\Plugins\NiagaraCore\FNiagaraCompileHash) > & InReferencedCompileHashes, [TArray](API\Runtime\Core\Containers\TArray)< [FString](API\Runtime\Core\Containers\FString) > & InReferencedObjs )